1. Field of the Invention
The present invention relates generally to the packaging of electronic components. More particularly, the present invention relates to a shielded electronic component module and method of fabricating the same.
2. Description of the Related Art
As the art moved to smaller, lighter weight, and higher frequency electronic devices such as cellular telephones, integrated circuit packages utilized in these electronic devices were increasingly placed closer to other electronic components and structures. Due to this reduced spacing, radiation such as electromagnetic or radio frequency (RF) radiation emanating from an integrated circuit package had a greater probability of interfering with the normal operation of an adjacent electronic component and vice versa. However, such interference was unacceptable depending upon the particular application.
Further, to prevent interfering with the normal operation of adjacent electronic devices, e.g., radio receivers, it was important to prevent the integrated circuit package from emanating unwanted radiation to the ambient air. Similarly, to prevent interfering with the normal operation of the integrated circuit package, it was important to protect the electronic component(s) of the integrated circuit package from radiation emanating from adjacent electronic devices, e.g., radio transmitters. Stated generally, it was important to prevent unwanted radiation from electronic component(s) of the integrated circuit package from reaching the surrounding air and vice versa.
To prevent unacceptable electromagnetic interference, a shielding system was used. Typically, an electrically conductive metallic enclosure was placed around the integrated circuit package after the integrated circuit package was mounted to the larger substrate such as the printed circuit mother board. However, fabricating such a metallic enclosure and separately attaching the metallic enclosure to the printed circuit mother board was relatively cumbersome, complex, and costly.
In accordance with the present invention, a transceiver package includes a substrate having an upper surface. An electronic component is mounted to the upper surface of the substrate. A shield encloses the electronic component and shields the electronic component from radiation. The transceiver package further includes an antenna and a dielectric cap. The dielectric cap is interposed between the shield and the antenna, the shield being a ground plane for the antenna.
Advantageously, the shield serves a least two functions. First, the shield shields the electronic component from radiation. More particularly, the shield prevents the electronic component from receiving unwanted radiation, e.g., generated by the antenna or receive from the surrounding air. Further, the shield prevents the electronic component from emanating unwanted radiation, e.g., to electronic components adjacent the transceiver package or to the surrounding air. Accordingly, the transceiver package in accordance with the present invention is well suited for wireless applications such as portable radio transmitters, portable telephones, portable radio receivers or other high frequency applications, which require shielding of electronic components.
Recall that in the prior art, shielding was accomplished by placing an electrically conductive metallic enclosure around the integrated circuit package after the integrated circuit package was mounted to the larger substrate such as the printed circuit mother board. By eliminating this electrically conductive metallic enclosure, an electronic device, e.g., cellular telephone, employing the transceiver package in accordance with the present invention is fabricated to be smaller, lighter and less expensive than an electronic device of the prior art.
Second, the shield is a ground plane for the antenna. Advantageously, the antenna is fabricated as part of the transceiver package. This is in stark contrast to the prior art where the antenna, which was a structure separate from the integrated circuit package, was attached separately to the printed circuit mother board.
By incorporating the antenna into the transceiver package, an electronic device, e.g., cellular telephone, employing the transceiver package in accordance with present invention is fabricated to be smaller, lighter and less expensive than an electronic device of the prior art.
Further, by incorporating the antenna into the transceiver package, the transceiver package is highly manufacturable compared to the prior art. As set forth above, the antenna of the prior art was attached separately to the printed circuit mother board. Disadvantageously, attaching the antenna at the printed circuit mother board stage of fabrication was labor intensive, complex and thus expensive. Further, specialized expertise, e.g., in RF circuitry, was required in designing and attaching the antenna to the printed circuit mother board.
In stark contrast to the prior art, the antenna is incorporated into the transceiver package. This simplifies manufacturing at the printed circuit mother board stage of fabrication thus reducing cost. Further, the transceiver package is an off-the-shelf part and no specialized expertise is required to use the transceiver package. This allows a wide variety of manufacturers to use the transceiver package to enter into the wireless marketplace.